JPH0428884Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a so-called truss bridge in which members are connected in a rigid frame structure.

[Prior Art] Conventional truss bridges have structures shown in FIGS. 11 to 18, and some have structures as shown in FIG. 19. In FIG. 11 to FIG. 18, 21 is an upper chord extending in the transverse direction, 22 is a lower chord extending parallel to the upper chord 21, and 21 is a lower chord extending parallel to the upper chord 21.
A diagonal member 23 and a vertical member 24 extend between the lower chord member 22 and the lower chord member 22 . Figure 13 shows the bottom end surface of an ordinary truss bridge (a truss bridge that becomes a quadrilateral truss when viewed in the longitudinal direction), and Figure 14 shows the bottom end surface of a triangular truss bridge (a truss bridge that becomes a rectangular truss when viewed in the longitudinal direction). This shows the bottom end of a truss bridge (a truss bridge). 1st
As can be seen from Figure 4, in the case of a triangular truss bridge,
Gusset A, the second fulcrum from the end of the truss bridge, is twisted.

[Problem that the idea aims to solve] The conventional truss bridge mentioned above had the following problems.

(b) All the vertical members 24 have the same length, and the truss bridge has the same height as the center up to the end. Excavation must be done, and a large amount of concrete material C is also required.

(b) In the case of a triangular truss bridge, it is necessary to twist the gusset A at the bridge point between the vertical member and the lower chord member, which is the second from the end of the truss bridge, and stress may be particularly concentrated in this part. This overlaps and causes a problem in terms of strength.

(c) In addition, there have been edge structures like the one shown in Figure 19 in the past, but in such cases, the distance between the bearing edge and the top edge of the substructure specified in the Highway Bridge Specifications S may not be protected, which is not good for earthquake resistance (as it may come off). Also, depending on the topography,
There is a high possibility that the ground in the shaded area in Figure 9 will be hit.
It may be necessary to excavate this part. Moreover, with this structure, the torsional rigidity of the fulcrum becomes zero, which is not preferable.

The present invention reduces the amount of excavation of the ground, eliminates the need to twist the gusset A at the point even in the case of a triangular truss bridge, and also reduces the distance between the bearing edge and the top edge of the substructure (Fig. 19). The object of the present invention is to provide a truss bridge that can provide a sufficient distance (S distance).

[Means for Solving the Problems] According to the present invention, the above problems are achieved by the truss bridge described below. In other words, in a truss bridge in which the upper chord member extending laterally, the lower chord member extending parallel to the lower chord member, and the vertical member extending vertically to connect the upper chord member and the lower chord member are connected in a rigid frame structure, The end vertical member, which is the end vertical member, is made shorter than the remaining vertical members, and the lower chord member is extended only between the case points of the second vertical member and the lower chord member from the end of the truss bridge. An end diagonal member extending diagonally upward toward the end of the truss bridge is provided between the point between the second vertical member from the end and the lower chord member and the point between the end vertical member and the upper chord member. , the upper and lower ends of the end diagonal member are connected to the upper chord member and the lower chord member, respectively, at respective case points, and the lower end of the end vertical member, the second vertical member from the end of the truss bridge, and the upper chord member are connected to each other. A fulcrum secondary diagonal member is provided that extends diagonally upward as it moves away from the end of the truss bridge, and the lower and upper ends of the fulcrum secondary diagonal member are connected at each case point. A truss bridge characterized by being connected to end vertical members and upper chord members.

[Function] In the above truss bridge, the amount of excavation of the ground is reduced because the end vertical members are short.

The bottom chord extends only from the end to the bottom of the second vertical member, which becomes the end of the bottom chord, and from there the end diagonal members extend diagonally upward, so even if it is a triangular truss bridge, it will not look like a continuous fulcrum. There is no need to twist the gusset itself, it can be installed diagonally with a free structure, and the end fulcrum is a free fulcrum and is not a constrained fulcrum that is subject to large stress concentration like the conventional second fulcrum. , the intensity becomes easier.

What extends from the lower point of the end vertical member is not an end diagonal member that extends diagonally downward as it moves away from the end toward the center, as in the conventional case, but in this invention, it is a fulcrum secondary diagonal member that extends diagonally upward. Therefore, even if the ground protrudes toward the end of the truss bridge, the truss bridge will not hit the ground, and the distance S between the support edge and the top edge of the substructure can be kept large, which is also favorable for earthquake resistance.

[Embodiments] Hereinafter, preferred embodiments of the truss bridge according to the present invention will be described with reference to the drawings from Fig. 1 to Fig. 10.

Figure 1 shows the truss bridge of the present invention viewed from above, Figure 2 shows the view from the front, Figure 3 shows the bottom of the square truss bridge, and Figure 4 shows the triangular truss bridge. 5 to 10 show the structure of each part viewed from the longitudinal direction.

As shown in the figure, the top chord 1 extends laterally (coinciding with, or substantially coincident with, the horizontal direction), and the bottom chord 2 extends below and parallel to the top chord 1 . Between the upper chord member 1 and the lower chord member 2, there is a diagonal member 3 extending diagonally.
A vertical member 4 extending perpendicularly is provided, the upper end of the diagonal member 3 and the upper end of the vertical member 4 are hinged to the upper chord member 1, the lower end of the diagonal member 3 and the lower end of the vertical member 4 are hinged to the lower chord member 2, In this way, they are connected in a truss shape, forming a so-called truss bridge. The connecting point is called a case point. The vertical member 4 at the end of the truss bridge in the longitudinal direction is an end vertical member 8
The diagonal member 3 at the end is called the end diagonal member 5 to distinguish it from the remaining vertical members and diagonal members.

The vertical members 8 are shorter than the remaining vertical members 4. In addition, the lower chord member 2 is 2 points from the end of the truss bridge.
It extends only between the case points P (one at each end of the bridge) between the th vertical member 4 and the lower chord member 2, and does not extend to the lower end fulcrum Q of the end vertical member 8. Between the fulcrum P between the second vertical member 4 and the lower chord member 2 from the end of the truss bridge and the point R between the end vertical member 8 and the upper chord member 1, there is a An end diagonal member 5 extending upward is provided, and the ends of this end diagonal member 5 are connected as hinges to the upper chord member 1 and the lower chord member 2 at respective fulcrums R and P, respectively. In addition, the lower end fulcrum Q of the end vertical member 8
A fulcrum secondary diagonal member 6 is provided between the fulcrum T of the second vertical member 4 from the end of the truss bridge and the upper chord member 1, and extends diagonally upward as the distance from the truss bridge end increases. The ends of this fulcrum sub diagonal member 6 are connected as hinges to the end vertical member 8 and the upper chord member 1 at respective fulcrums Q and T, respectively. The end diagonal members 5 and the case sub-diagonal members 6 are connected to each other at a fulcrum U as a hinge.

In addition, as other members, 9 is the lower chord material 2, 2
10 is a lower horizontal structure that extends obliquely to the lower chord 2 between the lower chord members 2 and 2, and 11 is a lower horizontal member that extends in a direction perpendicular to the lower chord member 2 between the upper chord members 1 and 1. 12 is a vertical beam extending parallel to the upper chord 1 between the upper chords 1 and 1, and 13 is a longitudinal beam extending parallel to the upper chord 1 between the upper chords 1 and 1. It is a crossbeam extending perpendicularly to the opposite direction. In addition, 14 is an end-to-tilt diagonal member, 15 is a shoe, 16 is an end-bottom horizontal structure, 17 is a fulcrum-to-tilt diagonal member, 18 is a floor slab, and 19
is an intermediate diagonal. Since members 9 to 19 also appear in conventional truss bridges, the same reference numerals are given to the conventional bridges shown in FIGS. 11 to 19.

Next, the effect will be explained.

Comparing FIG. 2 of the present invention with FIG. 12 of the conventional example, the difference between the present invention and the conventional one becomes clear.

In the conventional example, the end vertical members 28 have the same height as the central vertical members 24, so the bridge has a large height up to the bridge ends. In contrast, in the present invention, the end vertical members 8 are shorter in length in the vertical direction than the remaining vertical members 4. Therefore, the amount of excavation of the ground may be smaller than in the past, and the amount of concrete required for the concrete structure that supports the fulcrums that support both ends of the truss bridge is also small.

In addition, in the conventional triangular truss bridge shown in Fig. 14, the gusset A of the case point between the second vertical member 24 from the end and the lower chord member 22 requires twisting because this fulcrum is a continuous case point. However, in the present invention, the case point P is the farthest fulcrum when viewed from the lower chord member 2, allowing for flexible design, eliminating the need to twist the gusset, and since the farthest fulcrum is a free fulcrum, stress concentration is also reduced compared to the conventional one. The amount is extremely small compared to fulcrum A, and does not cause structural stress.

Furthermore, the diagonal member extending from the lower end fulcrum Q of the end vertical member 8, which is the end vertical member, is the fulcrum secondary diagonal member 7 extending diagonally upward from the end, so it cannot be connected to the ground or substructure located diagonally downward. There is no interference, and the distance S between the bearing edge and the top edge of the substructure shown in Figure 2
You can get a large amount. This completely prevents the end of the bridge from falling off the substructure during an earthquake, which is favorable for earthquake resistance.

[Effect of the idea] According to the present invention, the following effects are obtained.

(b) Only a small amount of excavation of the ground for the support points of the truss bridge is required, and a small amount of concrete is also required for the substructure, which has great economic merits.

(b) When used in a triangular truss bridge, it is desirable from the viewpoint of strength as no twisting of the gusset is required.

(c) The distance S between the support edge and the top edge of the substructure can be made large, which is desirable for earthquake resistance.

[Brief explanation of the drawing]

Figure 1 is a plan view of the truss bridge of the invention, Figure 2 is a front view of the truss bridge of the invention, Figure 3 is a bottom view of the truss bridge of the invention (square truss bridge), and Figure 4 is the invention of the invention. Figure 5 is a cross-sectional view on the fulcrum of the truss bridge of the present invention (square truss bridge), and Figure 6 is Figure 2 a- of the truss bridge of the present invention.
Figure 7 is a cross-sectional view along line a (square truss bridge), Figure 7 is a cross-sectional view on the fulcrum of the truss bridge of the present invention (triangular truss bridge), Figure 8 is Figure 2 a-a of the truss bridge of the present invention.
9 is a cross-sectional view along line b-b (square truss bridge) of the truss bridge of the present invention, and Figure 10 is a cross-sectional view of the truss bridge of the present invention. Figure 11 is a plan view of a conventional truss bridge, Figure 12 is a front view of a conventional truss bridge, and Figure 13 is a bottom view of a conventional truss bridge. (Square truss bridge), Figure 14 is a bottom view of a conventional truss bridge (triangular truss bridge), Figure 15 is a cross-sectional view of the fulcrum of a conventional truss bridge (square truss bridge), Figure 16 is a conventional truss bridge. Figure 17 is a cross-sectional view of the middle part of a bridge (square truss bridge), Figure 17 is a cross-sectional view of the fulcrum of a conventional truss bridge (triangular truss bridge), and Figure 18 is a cross-sectional view of the middle part of a conventional truss bridge (triangular truss bridge). Fig. 19 is a front view of the end structure of a conventional truss bridge. 1... Upper chord member, 2... Lower chord member, 3... Diagonal member, 4
... Vertical member, 5... End diagonal member, 6... Support secondary diagonal member,
7... End-to-end inclined lower chord member, 8... End vertical member.

Claims (1)

[Scope of utility model registration request] In a truss bridge that connects the upper chord member extending laterally, the lower chord member extending parallel to the upper chord member, and the vertical member extending vertically to connect the upper chord member and the lower chord member in a rigid frame structure, the end of the truss bridge The end vertical member, which is the vertical member of the truss bridge, is made shorter than the remaining vertical members, and the lower chord member is extended only between the points between the second vertical member and the lower chord member from the end of the truss bridge. An end diagonal member extending obliquely upward toward the end of the truss bridge is provided between the case point of the second vertical member and the lower chord member from the section and the case point of the end vertical member and the upper chord member. The upper and lower ends of the end diagonal members are connected to the top chord member and the lower chord member at their respective case points, and the lower end of the end vertical member and the case point between the second vertical member from the end of the truss bridge and the upper chord member. A fulcrum secondary diagonal member extending diagonally upward as it moves away from the truss bridge end is provided between the truss bridge end, and the lower and upper ends of the fulcrum secondary diagonal member are connected to end vertical members, respectively, at respective points. A truss bridge characterized by being connected to the upper chord.